You can see that in a typical gas system a tankless water heater with a capacity of 199 900 btu will require a 1 inch pipe size for a 20 ft branch length based on the 0 3 in w c.
Tankless water heater gas line requirements.
Tankless water heater pressure temperature relief valve safety requirements the temperature pressure relief valve lets water escape if the temperature or pressure is too high.
For both gas and electric models a tankless water heater s overall energy efficiency is measured using an energy factor ef rating.
This valve should be connected to a tube that discharges no more than six inches above floor level so hot water won t scald anyone nearby.
Ideally to maintain the water temperature required by all of these functions at the same time your requirements are a tankless water heater that is capable of raising the temperature of the water.
Ok so san jose has the following requirements for where to install the tankless water heater.
Drain and disconnect the old water heater.
Plumbing the most important skill is needed for working with both gas and water lines installing fixtures and ensuring there are no potential leaks or pressure issues.
This does not mean that a tankless water heater uses more gas.
Electrical even gas water heaters have electrical parts and need to be hooked up to your breaker box.
To heat the water quicker and more efficiently tankless water heaters operate with higher btus and require a minimum gas line.
Because tankless units heat water on demand they require higher btus or they operate on high heat.
This ef rating is based on test procedures developed by the u s.
Tankless water heaters usually need more gas than even the biggest home furnaces.
Rinnai tankless water heaters are designed to provide maximum performance and efficiency.
The minimum gas line size is inside diameter.
You may have to run new larger gas pipe from your gas meter.
Restrictions on gas fueled tankless water heaters no gas appliance may be located in a room used.
Vent termination all tankless water heater vents must terminate at least 4 feet from a property line.
The same appliance would require just a pipe size based on table 4 the 3 0 in w c.
Turn off the water gas supply valves and power.
A gas dryer cooktop together probably add up to 50 70 000btu hr the water heater is 180 000 so you need a minimum of 250k of capacity on a line that s shared and any tees off to the other load is best located within a couple feet of the meter regulator.